text: /*************************************************************************/
  /*  editor_file_system.cpp                                               */
  /*************************************************************************/
  /*                       This file is part of:                           */
  /*                           GODOT ENGINE                                */
  /*                      https://godotengine.org                          */
  /*************************************************************************/
  /* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur.                 */
  /* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md)    */
  /*                                                                       */
  /* Permission is hereby granted, free of charge, to any person obtaining */
  /* a copy of this software and associated documentation files (the       */
  /* "Software"), to deal in the Software without restriction, including   */
  /* without limitation the rights to use, copy, modify, merge, publish,   */
  /* distribute, sublicense, and/or sell copies of the Software, and to    */
  /* permit persons to whom the Software is furnished to do so, subject to */
  /* the following conditions:                                             */
  /*                                                                       */
  /* The above copyright notice and this permission notice shall be        */
  /* included in all copies or substantial portions of the Software.       */
  /*                                                                       */
  /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
  /* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
  /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
  /* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
  /* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
  /* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
  /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
  /*************************************************************************/
  
  #include "editor_file_system.h"
  
  #include "core/io/resource_importer.h"
  #include "core/io/resource_loader.h"
  #include "core/io/resource_saver.h"
  #include "core/os/file_access.h"
  #include "core/os/os.h"
  #include "core/project_settings.h"
  #include "core/variant_parser.h"
  #include "editor_node.h"
  #include "editor_resource_preview.h"
  #include "editor_settings.h"
  
  EditorFileSystem *EditorFileSystem::singleton = NULL;
  //the name is the version, to keep compatibility with different versions of Godot
  #define CACHE_FILE_NAME "filesystem_cache6"
  
  void EditorFileSystemDirectory::sort_files() {
  
  	files.sort_custom<FileInfoSort>();
  }
  
  int EditorFileSystemDirectory::find_file_index(const String &p_file) const {
  
  	for (int i = 0; i < files.size(); i++) {
  		if (files[i]->file == p_file)
  			return i;
  	}
  	return -1;
  }
  int EditorFileSystemDirectory::find_dir_index(const String &p_dir) const {
  
  	for (int i = 0; i < subdirs.size(); i++) {
  		if (subdirs[i]->name == p_dir)
  			return i;
  	}
  
  	return -1;
  }
  
  int EditorFileSystemDirectory::get_subdir_count() const {
  
  	return subdirs.size();
  }
  
  EditorFileSystemDirectory *EditorFileSystemDirectory::get_subdir(int p_idx) {
  
  	ERR_FAIL_INDEX_V(p_idx, subdirs.size(), NULL);
  	return subdirs[p_idx];
  }
  
  int EditorFileSystemDirectory::get_file_count() const {
  
  	return files.size();
  }
  
  String EditorFileSystemDirectory::get_file(int p_idx) const {
  
  	ERR_FAIL_INDEX_V(p_idx, files.size(), "");
  
  	return files[p_idx]->file;
  }
  
  String EditorFileSystemDirectory::get_path() const {
  
  	String p;
  	const EditorFileSystemDirectory *d = this;
  	while (d->parent) {
  		p = d->name.plus_file(p);
  		d = d->parent;
  	}
  
  	return "res://" + p;
  }
  
  String EditorFileSystemDirectory::get_file_path(int p_idx) const {
  
  	String file = get_file(p_idx);
  	const EditorFileSystemDirectory *d = this;
  	while (d->parent) {
  		file = d->name.plus_file(file);
  		d = d->parent;
  	}
  
  	return "res://" + file;
  }
  
  Vector<String> EditorFileSystemDirectory::get_file_deps(int p_idx) const {
  
  	ERR_FAIL_INDEX_V(p_idx, files.size(), Vector<String>());
  	return files[p_idx]->deps;
  }
  
  bool EditorFileSystemDirectory::get_file_import_is_valid(int p_idx) const {
  
  	ERR_FAIL_INDEX_V(p_idx, files.size(), false);
  	return files[p_idx]->import_valid;
  }
  
  String EditorFileSystemDirectory::get_file_script_class_name(int p_idx) const {
  	return files[p_idx]->script_class_name;
  }
  
  String EditorFileSystemDirectory::get_file_script_class_extends(int p_idx) const {
  	return files[p_idx]->script_class_extends;
  }
  
  String EditorFileSystemDirectory::get_file_script_class_icon_path(int p_idx) const {
  	return files[p_idx]->script_class_icon_path;
  }
  
  StringName EditorFileSystemDirectory::get_file_type(int p_idx) const {
  
  	ERR_FAIL_INDEX_V(p_idx, files.size(), "");
  	return files[p_idx]->type;
  }
  
  String EditorFileSystemDirectory::get_name() {
  
  	return name;
  }
  
  EditorFileSystemDirectory *EditorFileSystemDirectory::get_parent() {
  
  	return parent;
  }
  
  void EditorFileSystemDirectory::_bind_methods() {
  
  	ClassDB::bind_method(D_METHOD("get_subdir_count"), &EditorFileSystemDirectory::get_subdir_count);
  	ClassDB::bind_method(D_METHOD("get_subdir", "idx"), &EditorFileSystemDirectory::get_subdir);
  	ClassDB::bind_method(D_METHOD("get_file_count"), &EditorFileSystemDirectory::get_file_count);
  	ClassDB::bind_method(D_METHOD("get_file", "idx"), &EditorFileSystemDirectory::get_file);
  	ClassDB::bind_method(D_METHOD("get_file_path", "idx"), &EditorFileSystemDirectory::get_file_path);
  	ClassDB::bind_method(D_METHOD("get_file_type", "idx"), &EditorFileSystemDirectory::get_file_type);
  	ClassDB::bind_method(D_METHOD("get_file_script_class_name", "idx"), &EditorFileSystemDirectory::get_file_script_class_name);
  	ClassDB::bind_method(D_METHOD("get_file_script_class_extends", "idx"), &EditorFileSystemDirectory::get_file_script_class_extends);
  	ClassDB::bind_method(D_METHOD("get_file_import_is_valid", "idx"), &EditorFileSystemDirectory::get_file_import_is_valid);
  	ClassDB::bind_method(D_METHOD("get_name"), &EditorFileSystemDirectory::get_name);
  	ClassDB::bind_method(D_METHOD("get_path"), &EditorFileSystemDirectory::get_path);
  	ClassDB::bind_method(D_METHOD("get_parent"), &EditorFileSystemDirectory::get_parent);
  	ClassDB::bind_method(D_METHOD("find_file_index", "name"), &EditorFileSystemDirectory::find_file_index);
  	ClassDB::bind_method(D_METHOD("find_dir_index", "name"), &EditorFileSystemDirectory::find_dir_index);
  }
  
  EditorFileSystemDirectory::EditorFileSystemDirectory() {
  
  	modified_time = 0;
  	parent = NULL;
  	verified = false;
  }
  
  EditorFileSystemDirectory::~EditorFileSystemDirectory() {
  
  	for (int i = 0; i < files.size(); i++) {
  
  		memdelete(files[i]);
  	}
  
  	for (int i = 0; i < subdirs.size(); i++) {
  
  		memdelete(subdirs[i]);
  	}
  }
  
  void EditorFileSystem::_scan_filesystem() {
  
  	ERR_FAIL_COND(!scanning || new_filesystem);
  
  	//read .fscache
  	String cpath;
  
  	sources_changed.clear();
  	file_cache.clear();
  
  	String project = ProjectSettings::get_singleton()->get_resource_path();
  
  	String fscache = EditorSettings::get_singleton()->get_project_settings_dir().plus_file(CACHE_FILE_NAME);
  	FileAccess *f = FileAccess::open(fscache, FileAccess::READ);
  
  	bool first = true;
  	if (f) {
  		//read the disk cache
  		while (!f->eof_reached()) {
  
  			String l = f->get_line().strip_edges();
  			if (first) {
  				if (first_scan) {
  					// only use this on first scan, afterwards it gets ignored
  					// this is so on first reimport we synchronize versions, then
  					// we don't care until editor restart. This is for usability mainly so
  					// your workflow is not killed after changing a setting by forceful reimporting
  					// everything there is.
  					filesystem_settings_version_for_import = l.strip_edges();
  					if (filesystem_settings_version_for_import != ResourceFormatImporter::get_singleton()->get_import_settings_hash()) {
  						revalidate_import_files = true;
  					}
  				}
  				first = false;
  				continue;
  			}
  			if (l == String())
  				continue;
  
  			if (l.begins_with("::")) {
  				Vector<String> split = l.split("::");
  				ERR_CONTINUE(split.size() != 3);
  				String name = split[1];
  
  				cpath = name;
  
  			} else {
  				Vector<String> split = l.split("::");
  				ERR_CONTINUE(split.size() != 8);
  				String name = split[0];
  				String file;
  
  				file = name;
  				name = cpath.plus_file(name);
  
  				FileCache fc;
  				fc.type = split[1];
  				fc.modification_time = split[2].to_int64();
  				fc.import_modification_time = split[3].to_int64();
  				fc.import_valid = split[4].to_int64() != 0;
  				fc.import_group_file = split[5].strip_edges();
  				fc.script_class_name = split[6].get_slice("<>", 0);
  				fc.script_class_extends = split[6].get_slice("<>", 1);
  				fc.script_class_icon_path = split[6].get_slice("<>", 2);
  
  				String deps = split[7].strip_edges();
  				if (deps.length()) {
  					Vector<String> dp = deps.split("<>");
  					for (int i = 0; i < dp.size(); i++) {
  						String path = dp[i];
  						fc.deps.push_back(path);
  					}
  				}
  
  				file_cache[name] = fc;
  			}
  		}
  
  		f->close();
  		memdelete(f);
  	}
  
  	String update_cache = EditorSettings::get_singleton()->get_project_settings_dir().plus_file("filesystem_update4");
  
  	if (FileAccess::exists(update_cache)) {
  		{
  			FileAccessRef f2 = FileAccess::open(update_cache, FileAccess::READ);
  			String l = f2->get_line().strip_edges();
  			while (l != String()) {
  
  				file_cache.erase(l); //erase cache for this, so it gets updated
  				l = f2->get_line().strip_edges();
  			}
  		}
  
  		DirAccessRef d = DirAccess::create(DirAccess::ACCESS_FILESYSTEM);
  		d->remove(update_cache); //bye bye update cache
  	}
  
  	EditorProgressBG scan_progress("efs", "ScanFS", 1000);
  
  	ScanProgress sp;
  	sp.low = 0;
  	sp.hi = 1;
  	sp.progress = &scan_progress;
  
  	new_filesystem = memnew(EditorFileSystemDirectory);
  	new_filesystem->parent = NULL;
  
  	DirAccess *d = DirAccess::create(DirAccess::ACCESS_RESOURCES);
  	d->change_dir("res://");
  	_scan_new_dir(new_filesystem, d, sp);
  
  	file_cache.clear(); //clear caches, no longer needed
  
  	memdelete(d);
  
  	if (!first_scan) {
  		//on the first scan this is done from the main thread after re-importing
  		_save_filesystem_cache();
  	}
  
  	scanning = false;
  }
  
  void EditorFileSystem::_save_filesystem_cache() {
  
  	group_file_cache.clear();
  
  	String fscache = EditorSettings::get_singleton()->get_project_settings_dir().plus_file(CACHE_FILE_NAME);
  
  	FileAccess *f = FileAccess::open(fscache, FileAccess::WRITE);
  	if (f == NULL) {
  		ERR_PRINTS("Error writing fscache: " + fscache);
  	} else {
  		f->store_line(filesystem_settings_version_for_import);
  		_save_filesystem_cache(filesystem, f);
  		f->close();
  		memdelete(f);
  	}
  }
  
  void EditorFileSystem::_thread_func(void *_userdata) {
  
  	EditorFileSystem *sd = (EditorFileSystem *)_userdata;
  	sd->_scan_filesystem();
  }
  
  bool EditorFileSystem::_test_for_reimport(const String &p_path, bool p_only_imported_files) {
  
  	if (!reimport_on_missing_imported_files && p_only_imported_files)
  		return false;
  
  	if (!FileAccess::exists(p_path + ".import")) {
  		return true;
  	}
  
  	if (!ResourceFormatImporter::get_singleton()->are_import_settings_valid(p_path)) {
  		//reimport settings are not valid, reimport
  		return true;
  	}
  
  	Error err;
  	FileAccess *f = FileAccess::open(p_path + ".import", FileAccess::READ, &err);
  
  	if (!f) { //no import file, do reimport
  		return true;
  	}
  
  	VariantParser::StreamFile stream;
  	stream.f = f;
  
  	String assign;
  	Variant value;
  	VariantParser::Tag next_tag;
  
  	int lines = 0;
  	String error_text;
  
  	List<String> to_check;
  
  	String source_file = "";
  	String source_md5 = "";
  	Vector<String> dest_files;
  	String dest_md5 = "";
  
  	while (true) {
  
  		assign = Variant();
  		next_tag.fields.clear();
  		next_tag.name = String();
  
  		err = VariantParser::parse_tag_assign_eof(&stream, lines, error_text, next_tag, assign, value, NULL, true);
  		if (err == ERR_FILE_EOF) {
  			break;
  		} else if (err != OK) {
  			ERR_PRINTS("ResourceFormatImporter::load - " + p_path + ".import:" + itos(lines) + " error: " + error_text);
  			memdelete(f);
  			return false; //parse error, try reimport manually (Avoid reimport loop on broken file)
  		}
  
  		if (assign != String()) {
  			if (assign.begins_with("path")) {
  				to_check.push_back(value);
  			} else if (assign == "files") {
  				Array fa = value;
  				for (int i = 0; i < fa.size(); i++) {
  					to_check.push_back(fa[i]);
  				}
  			} else if (!p_only_imported_files) {
  				if (assign == "source_file") {
  					source_file = value;
  				} else if (assign == "dest_files") {
  					dest_files = value;
  				}
  			}
  
  		} else if (next_tag.name != "remap" && next_tag.name != "deps") {
  			break;
  		}
  	}
  
  	memdelete(f);
  
  	// Read the md5's from a separate file (so the import parameters aren't dependent on the file version
  	String base_path = ResourceFormatImporter::get_singleton()->get_import_base_path(p_path);
  	FileAccess *md5s = FileAccess::open(base_path + ".md5", FileAccess::READ, &err);
  	if (!md5s) { // No md5's stored for this resource
  		return true;
  	}
  
  	VariantParser::StreamFile md5_stream;
  	md5_stream.f = md5s;
  
  	while (true) {
  		assign = Variant();
  		next_tag.fields.clear();
  		next_tag.name = String();
  
  		err = VariantParser::parse_tag_assign_eof(&md5_stream, lines, error_text, next_tag, assign, value, NULL, true);
  
  		if (err == ERR_FILE_EOF) {
  			break;
  		} else if (err != OK) {
  			ERR_PRINTS("ResourceFormatImporter::load - " + p_path + ".import.md5:" + itos(lines) + " error: " + error_text);
  			memdelete(md5s);
  			return false; // parse error
  		}
  		if (assign != String()) {
  			if (!p_only_imported_files) {
  				if (assign == "source_md5") {
  					source_md5 = value;
  				} else if (assign == "dest_md5") {
  					dest_md5 = value;
  				}
  			}
  		}
  	}
  	memdelete(md5s);
  
  	//imported files are gone, reimport
  	for (List<String>::Element *E = to_check.front(); E; E = E->next()) {
  		if (!FileAccess::exists(E->get())) {
  			return true;
  		}
  	}
  
  	//check source md5 matching
  	if (!p_only_imported_files) {
  
  		if (source_file != String() && source_file != p_path) {
  			return true; //file was moved, reimport
  		}
  
  		if (source_md5 == String()) {
  			return true; //lacks md5, so just reimport
  		}
  
  		String md5 = FileAccess::get_md5(p_path);
  		if (md5 != source_md5) {
  			return true;
  		}
  
  		if (dest_files.size() && dest_md5 != String()) {
  			md5 = FileAccess::get_multiple_md5(dest_files);
  			if (md5 != dest_md5) {
  				return true;
  			}
  		}
  	}
  
  	return false; //nothing changed
  }
  
  bool EditorFileSystem::_update_scan_actions() {
  
  	sources_changed.clear();
  
  	bool fs_changed = false;
  
  	Vector<String> reimports;
  	Vector<String> reloads;
  
  	for (List<ItemAction>::Element *E = scan_actions.front(); E; E = E->next()) {
  
  		ItemAction &ia = E->get();
  
  		switch (ia.action) {
  			case ItemAction::ACTION_NONE: {
  
  			} break;
  			case ItemAction::ACTION_DIR_ADD: {
  
  				int idx = 0;
  				for (int i = 0; i < ia.dir->subdirs.size(); i++) {
  
  					if (ia.new_dir->name < ia.dir->subdirs[i]->name)
  						break;
  					idx++;
  				}
  				if (idx == ia.dir->subdirs.size()) {
  					ia.dir->subdirs.push_back(ia.new_dir);
  				} else {
  					ia.dir->subdirs.insert(idx, ia.new_dir);
  				}
  
  				fs_changed = true;
  			} break;
  			case ItemAction::ACTION_DIR_REMOVE: {
  
  				ERR_CONTINUE(!ia.dir->parent);
  				ia.dir->parent->subdirs.erase(ia.dir);
  				memdelete(ia.dir);
  				fs_changed = true;
  			} break;
  			case ItemAction::ACTION_FILE_ADD: {
  
  				int idx = 0;
  				for (int i = 0; i < ia.dir->files.size(); i++) {
  
  					if (ia.new_file->file < ia.dir->files[i]->file)
  						break;
  					idx++;
  				}
  				if (idx == ia.dir->files.size()) {
  					ia.dir->files.push_back(ia.new_file);
  				} else {
  					ia.dir->files.insert(idx, ia.new_file);
  				}
  
  				fs_changed = true;
  
  			} break;
  			case ItemAction::ACTION_FILE_REMOVE: {
  
  				int idx = ia.dir->find_file_index(ia.file);
  				ERR_CONTINUE(idx == -1);
  				_delete_internal_files(ia.dir->files[idx]->file);
  				memdelete(ia.dir->files[idx]);
  				ia.dir->files.remove(idx);
  
  				fs_changed = true;
  
  			} break;
  			case ItemAction::ACTION_FILE_TEST_REIMPORT: {
  
  				int idx = ia.dir->find_file_index(ia.file);
  				ERR_CONTINUE(idx == -1);
  				String full_path = ia.dir->get_file_path(idx);
  				if (_test_for_reimport(full_path, false)) {
  					//must reimport
  					reimports.push_back(full_path);
  				} else {
  					//must not reimport, all was good
  					//update modified times, to avoid reimport
  					ia.dir->files[idx]->modified_time = FileAccess::get_modified_time(full_path);
  					ia.dir->files[idx]->import_modified_time = FileAccess::get_modified_time(full_path + ".import");
  				}
  
  				fs_changed = true;
  			} break;
  			case ItemAction::ACTION_FILE_RELOAD: {
  
  				int idx = ia.dir->find_file_index(ia.file);
  				ERR_CONTINUE(idx == -1);
  				String full_path = ia.dir->get_file_path(idx);
  
  				reloads.push_back(full_path);
  
  			} break;
  		}
  	}
  
  	if (reimports.size()) {
  		reimport_files(reimports);
  	}
  
  	if (first_scan) {
  		//only on first scan this is valid and updated, then settings changed.
  		revalidate_import_files = false;
  		filesystem_settings_version_for_import = ResourceFormatImporter::get_singleton()->get_import_settings_hash();
  		_save_filesystem_cache();
  	}
  
  	if (reloads.size()) {
  		emit_signal("resources_reload", reloads);
  	}
  	scan_actions.clear();
  
  	return fs_changed;
  }
  
  void EditorFileSystem::scan() {
  
  	if (false /*&& bool(Globals::get_singleton()->get("debug/disable_scan"))*/)
  		return;
  
  	if (scanning || scanning_changes || thread)
  		return;
  
  	_update_extensions();
  
  	abort_scan = false;
  	if (!use_threads) {
  		scanning = true;
  		scan_total = 0;
  		_scan_filesystem();
  		if (filesystem)
  			memdelete(filesystem);
  		//file_type_cache.clear();
  		filesystem = new_filesystem;
  		new_filesystem = NULL;
  		_update_scan_actions();
  		scanning = false;
  		emit_signal("filesystem_changed");
  		emit_signal("sources_changed", sources_changed.size() > 0);
  		_queue_update_script_classes();
  		first_scan = false;
  	} else {
  
  		ERR_FAIL_COND(thread);
  		set_process(true);
  		Thread::Settings s;
  		scanning = true;
  		scan_total = 0;
  		s.priority = Thread::PRIORITY_LOW;
  		thread = Thread::create(_thread_func, this, s);
  		//tree->hide();
  		//progress->show();
  	}
  }
  
  void EditorFileSystem::ScanProgress::update(int p_current, int p_total) const {
  
  	float ratio = low + ((hi - low) / p_total) * p_current;
  	progress->step(ratio * 1000);
  	EditorFileSystem::singleton->scan_total = ratio;
  }
  
  EditorFileSystem::ScanProgress EditorFileSystem::ScanProgress::get_sub(int p_current, int p_total) const {
  
  	ScanProgress sp = *this;
  	float slice = (sp.hi - sp.low) / p_total;
  	sp.low += slice * p_current;
  	sp.hi = slice;
  	return sp;
  }
  
  void EditorFileSystem::_scan_new_dir(EditorFileSystemDirectory *p_dir, DirAccess *da, const ScanProgress &p_progress) {
  
  	List<String> dirs;
  	List<String> files;
  
  	String cd = da->get_current_dir();
  
  	p_dir->modified_time = FileAccess::get_modified_time(cd);
  
  	da->list_dir_begin();
  	while (true) {
  
  		String f = da->get_next();
  		if (f == "")
  			break;
  
  		if (da->current_is_dir()) {
  
  			if (f.begins_with(".")) //ignore hidden and . / ..
  				continue;
  
  			if (FileAccess::exists(cd.plus_file(f).plus_file("project.godot"))) // skip if another project inside this
  				continue;
  			if (FileAccess::exists(cd.plus_file(f).plus_file(".gdignore"))) // skip if another project inside this
  				continue;
  
  			dirs.push_back(f);
  
  		} else {
  
  			files.push_back(f);
  		}
  	}
  
  	da->list_dir_end();
  
  	dirs.sort_custom<NaturalNoCaseComparator>();
  	files.sort_custom<NaturalNoCaseComparator>();
  
  	int total = dirs.size() + files.size();
  	int idx = 0;
  
  	for (List<String>::Element *E = dirs.front(); E; E = E->next(), idx++) {
  
  		if (da->change_dir(E->get()) == OK) {
  
  			String d = da->get_current_dir();
  
  			if (d == cd || !d.begins_with(cd)) {
  				da->change_dir(cd); //avoid recursion
  			} else {
  
  				EditorFileSystemDirectory *efd = memnew(EditorFileSystemDirectory);
  
  				efd->parent = p_dir;
  				efd->name = E->get();
  
  				_scan_new_dir(efd, da, p_progress.get_sub(idx, total));
  
  				int idx2 = 0;
  				for (int i = 0; i < p_dir->subdirs.size(); i++) {
  
  					if (efd->name < p_dir->subdirs[i]->name)
  						break;
  					idx2++;
  				}
  				if (idx2 == p_dir->subdirs.size()) {
  					p_dir->subdirs.push_back(efd);
  				} else {
  					p_dir->subdirs.insert(idx2, efd);
  				}
  
  				da->change_dir("..");
  			}
  		} else {
  			ERR_PRINTS("Cannot go into subdir: " + E->get());
  		}
  
  		p_progress.update(idx, total);
  	}
  
  	for (List<String>::Element *E = files.front(); E; E = E->next(), idx++) {
  
  		String ext = E->get().get_extension().to_lower();
  		if (!valid_extensions.has(ext)) {
  			continue; //invalid
  		}
  
  		EditorFileSystemDirectory::FileInfo *fi = memnew(EditorFileSystemDirectory::FileInfo);
  		fi->file = E->get();
  
  		String path = cd.plus_file(fi->file);
  
  		FileCache *fc = file_cache.getptr(path);
  		uint64_t mt = FileAccess::get_modified_time(path);
  
  		if (import_extensions.has(ext)) {
  
  			//is imported
  			uint64_t import_mt = 0;
  			if (FileAccess::exists(path + ".import")) {
  				import_mt = FileAccess::get_modified_time(path + ".import");
  			}
  
  			if (fc && fc->modification_time == mt && fc->import_modification_time == import_mt && !_test_for_reimport(path, true)) {
  
  				fi->type = fc->type;
  				fi->deps = fc->deps;
  				fi->modified_time = fc->modification_time;
  				fi->import_modified_time = fc->import_modification_time;
  
  				fi->import_valid = fc->import_valid;
  				fi->script_class_name = fc->script_class_name;
  				fi->import_group_file = fc->import_group_file;
  				fi->script_class_extends = fc->script_class_extends;
  				fi->script_class_icon_path = fc->script_class_icon_path;
  
  				if (revalidate_import_files && !ResourceFormatImporter::get_singleton()->are_import_settings_valid(path)) {
  					ItemAction ia;
  					ia.action = ItemAction::ACTION_FILE_TEST_REIMPORT;
  					ia.dir = p_dir;
  					ia.file = E->get();
  					scan_actions.push_back(ia);
  				}
  
  				if (fc->type == String()) {
  					fi->type = ResourceLoader::get_resource_type(path);
  					fi->import_group_file = ResourceLoader::get_import_group_file(path);
  					//there is also the chance that file type changed due to reimport, must probably check this somehow here (or kind of note it for next time in another file?)
  					//note: I think this should not happen any longer..
  				}
  
  			} else {
  
  				fi->type = ResourceFormatImporter::get_singleton()->get_resource_type(path);
  				fi->import_group_file = ResourceFormatImporter::get_singleton()->get_import_group_file(path);
  				fi->script_class_name = _get_global_script_class(fi->type, path, &fi->script_class_extends, &fi->script_class_icon_path);
  				fi->modified_time = 0;
  				fi->import_modified_time = 0;
  				fi->import_valid = ResourceLoader::is_import_valid(path);
  
  				ItemAction ia;
  				ia.action = ItemAction::ACTION_FILE_TEST_REIMPORT;
  				ia.dir = p_dir;
  				ia.file = E->get();
  				scan_actions.push_back(ia);
  			}
  		} else {
  
  			if (fc && fc->modification_time == mt) {
  				//not imported, so just update type if changed
  				fi->type = fc->type;
  				fi->modified_time = fc->modification_time;
  				fi->deps = fc->deps;
  				fi->import_modified_time = 0;
  				fi->import_valid = true;
  				fi->script_class_name = fc->script_class_name;
  				fi->script_class_extends = fc->script_class_extends;
  				fi->script_class_icon_path = fc->script_class_icon_path;
  			} else {
  				//new or modified time
  				fi->type = ResourceLoader::get_resource_type(path);
  				fi->script_class_name = _get_global_script_class(fi->type, path, &fi->script_class_extends, &fi->script_class_icon_path);
  				fi->deps = _get_dependencies(path);
  				fi->modified_time = mt;
  				fi->import_modified_time = 0;
  				fi->import_valid = true;
  			}
  		}
  
  		p_dir->files.push_back(fi);
  		p_progress.update(idx, total);
  	}
  }
  
  void EditorFileSystem::_scan_fs_changes(EditorFileSystemDirectory *p_dir, const ScanProgress &p_progress) {
  
  	uint64_t current_mtime = FileAccess::get_modified_time(p_dir->get_path());
  
  	bool updated_dir = false;
  	String cd = p_dir->get_path();
  
  	if (current_mtime != p_dir->modified_time || using_fat32_or_exfat) {
  
  		updated_dir = true;
  		p_dir->modified_time = current_mtime;
  		//ooooops, dir changed, see what's going on
  
  		//first mark everything as veryfied
  
  		for (int i = 0; i < p_dir->files.size(); i++) {
  
  			p_dir->files[i]->verified = false;
  		}
  
  		for (int i = 0; i < p_dir->subdirs.size(); i++) {
  
  			p_dir->get_subdir(i)->verified = false;
  		}
  
  		//then scan files and directories and check what's different
  
  		DirAccess *da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
  
  		da->change_dir(cd);
  		da->list_dir_begin();
  		while (true) {
  
  			String f = da->get_next();
  			if (f == "")
  				break;
  
  			if (da->current_is_dir()) {
  
  				if (f.begins_with(".")) //ignore hidden and . / ..
  					continue;
  
  				int idx = p_dir->find_dir_index(f);
  				if (idx == -1) {
  
  					if (FileAccess::exists(cd.plus_file(f).plus_file("project.godot"))) // skip if another project inside this
  						continue;
  					if (FileAccess::exists(cd.plus_file(f).plus_file(".gdignore"))) // skip if another project inside this
  						continue;
  
  					EditorFileSystemDirectory *efd = memnew(EditorFileSystemDirectory);
  
  					efd->parent = p_dir;
  					efd->name = f;
  					DirAccess *d = DirAccess::create(DirAccess::ACCESS_RESOURCES);
  					d->change_dir(cd.plus_file(f));
  					_scan_new_dir(efd, d, p_progress.get_sub(1, 1));
  					memdelete(d);
  
  					ItemAction ia;
  					ia.action = ItemAction::ACTION_DIR_ADD;
  					ia.dir = p_dir;
  					ia.file = f;
  					ia.new_dir = efd;
  					scan_actions.push_back(ia);
  				} else {
  					p_dir->subdirs[idx]->verified = true;
  				}
  
  			} else {
  				String ext = f.get_extension().to_lower();
  				if (!valid_extensions.has(ext))
  					continue; //invalid
  
  				int idx = p_dir->find_file_index(f);
  
  				if (idx == -1) {
  					//never seen this file, add actition to add it
  					EditorFileSystemDirectory::FileInfo *fi = memnew(EditorFileSystemDirectory::FileInfo);
  					fi->file = f;
  
  					String path = cd.plus_file(fi->file);
  					fi->modified_time = FileAccess::get_modified_time(path);
  					fi->import_modified_time = 0;
  					fi->type = ResourceLoader::get_resource_type(path);
  					fi->script_class_name = _get_global_script_class(fi->type, path, &fi->script_class_extends, &fi->script_class_icon_path);
  					fi->import_valid = ResourceLoader::is_import_valid(path);
  					fi->import_group_file = ResourceLoader::get_import_group_file(path);
  
  					{
  						ItemAction ia;
  						ia.action = ItemAction::ACTION_FILE_ADD;
  						ia.dir = p_dir;
  						ia.file = f;
  						ia.new_file = fi;
  						scan_actions.push_back(ia);
  					}
  
  					if (import_extensions.has(ext)) {
  						//if it can be imported, and it was added, it needs to be reimported
  						ItemAction ia;
  						ia.action = ItemAction::ACTION_FILE_TEST_REIMPORT;
  						ia.dir = p_dir;
  						ia.file = f;
  						scan_actions.push_back(ia);
  					}
  
  				} else {
  					p_dir->files[idx]->verified = true;
  				}
  			}
  		}
  
  		da->list_dir_end();
  		memdelete(da);
  	}
  
  	for (int i = 0; i < p_dir->files.size(); i++) {
  
  		if (updated_dir && !p_dir->files[i]->verified) {
  			//this file was removed, add action to remove it
  			ItemAction ia;
  			ia.action = ItemAction::ACTION_FILE_REMOVE;
  			ia.dir = p_dir;
  			ia.file = p_dir->files[i]->file;
  			scan_actions.push_back(ia);
  			continue;
  		}
  
  		String path = cd.plus_file(p_dir->files[i]->file);
  
  		if (import_extensions.has(p_dir->files[i]->file.get_extension().to_lower())) {
  			//check here if file must be imported or not
  
  			uint64_t mt = FileAccess::get_modified_time(path);
  
  			bool reimport = false;
  
  			if (mt != p_dir->files[i]->modified_time) {
  				reimport = true; //it was modified, must be reimported.
  			} else if (!FileAccess::exists(path + ".import")) {
  				reimport = true; //no .import file, obviously reimport
  			} else {
  
  				uint64_t import_mt = FileAccess::get_modified_time(path + ".import");
  				if (import_mt != p_dir->files[i]->import_modified_time) {
  					reimport = true;
  				} else if (_test_for_reimport(path, true)) {
  					reimport = true;
  				}
  			}
  
  			if (reimport) {
  
  				ItemAction ia;
  				ia.action = ItemAction::ACTION_FILE_TEST_REIMPORT;
  				ia.dir = p_dir;
  				ia.file = p_dir->files[i]->file;
  				scan_actions.push_back(ia);
  			}
  		} else if (ResourceCache::has(path)) { //test for potential reload
  
  			uint64_t mt = FileAccess::get_modified_time(path);
  
  			if (mt != p_dir->files[i]->modified_time) {
  
  				p_dir->files[i]->modified_time = mt; //save new time, but test for reload
  
  				ItemAction ia;
  				ia.action = ItemAction::ACTION_FILE_RELOAD;
  				ia.dir = p_dir;
  				ia.file = p_dir->files[i]->file;
  				scan_actions.push_back(ia);
  			}
  		}
  	}
  
  	for (int i = 0; i < p_dir->subdirs.size(); i++) {
  
  		if (updated_dir && !p_dir->subdirs[i]->verified) {
  			//this directory was removed, add action to remove it
  			ItemAction ia;
  			ia.action = ItemAction::ACTION_DIR_REMOVE;
  			ia.dir = p_dir->subdirs[i];
  			scan_actions.push_back(ia);
  			continue;
  		}
  		_scan_fs_changes(p_dir->get_subdir(i), p_progress);
  	}
  }
  
  void EditorFileSystem::_delete_internal_files(String p_file) {
  	if (FileAccess::exists(p_file + ".import")) {
  		List<String> paths;
  		ResourceFormatImporter::get_singleton()->get_internal_resource_path_list(p_file, &paths);
  		DirAccess *da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
  		for (List<String>::Element *E = paths.front(); E; E = E->next()) {
  			da->remove(E->get());
  		}
  		da->remove(p_file + ".import");
  		memdelete(da);
  	}
  }
  
  void EditorFileSystem::_thread_func_sources(void *_userdata) {
  
  	EditorFileSystem *efs = (EditorFileSystem *)_userdata;
  	if (efs->filesystem) {
  		EditorProgressBG pr("sources", TTR("ScanSources"), 1000);
  		ScanProgress sp;
  		sp.progress = &pr;
  		sp.hi = 1;
  		sp.low = 0;
  		efs->_scan_fs_changes(efs->filesystem, sp);
  	}
  	efs->scanning_changes_done = true;
  }
  
  void EditorFileSystem::get_changed_sources(List<String> *r_changed) {
  
  	*r_changed = sources_changed;
  }
  
  void EditorFileSystem::scan_changes() {
  
  	if (scanning || scanning_changes || thread)
  		return;
  
  	_update_extensions();
  	sources_changed.clear();
  	scanning_changes = true;
  	scanning_changes_done = false;
  
  	abort_scan = false;
  
  	if (!use_threads) {
  		if (filesystem) {
  			EditorProgressBG pr("sources", TTR("ScanSources"), 1000);
  			ScanProgress sp;
  			sp.progress = &pr;
  			sp.hi = 1;
  			sp.low = 0;
  			scan_total = 0;
  			_scan_fs_changes(filesystem, sp);
  			if (_update_scan_actions())
  				emit_signal("filesystem_changed");
  		}
  		scanning_changes = false;
  		scanning_changes_done = true;
  		emit_signal("sources_changed", sources_changed.size() > 0);
  	} else {
  
  		ERR_FAIL_COND(thread_sources);
  		set_process(true);
  		scan_total = 0;
  		Thread::Settings s;
  		s.priority = Thread::PRIORITY_LOW;
  		thread_sources = Thread::create(_thread_func_sources, this, s);
  	}
  }
  
  void EditorFileSystem::_notification(int p_what) {
  
  	switch (p_what) {
  
  		case NOTIFICATION_ENTER_TREE: {
  
  			call_deferred("scan"); //this should happen after every editor node entered the tree
  
  		} break;
  		case NOTIFICATION_EXIT_TREE: {
  			if (use_threads && thread) {
  				//abort thread if in progress
  				abort_scan = true;
  				while (scanning) {
  					OS::get_singleton()->delay_usec(1000);
  				}
  				Thread::wait_to_finish(thread);
  				memdelete(thread);
  				thread = NULL;
  				WARN_PRINTS("Scan thread aborted...");
  				set_process(false);
  			}
  
  			if (filesystem)
  				memdelete(filesystem);
  			if (new_filesystem)
  				memdelete(new_filesystem);
  			filesystem = NULL;
  			new_filesystem = NULL;
  
  		} break;
  		case NOTIFICATION_PROCESS: {
  
  			if (use_threads) {
  
  				if (scanning_changes) {
  
  					if (scanning_changes_done) {
  
  						scanning_changes = false;
  
  						set_process(false);
  
  						Thread::wait_to_finish(thread_sources);
  						memdelete(thread_sources);
  						thread_sources = NULL;
  						if (_update_scan_actions())
  							emit_signal("filesystem_changed");
  						emit_signal("sources_changed", sources_changed.size() > 0);
  						_queue_update_script_classes();
  						first_scan = false;
  					}
  				} else if (!scanning) {
  
  					set_process(false);
  
  					if (filesystem)
  						memdelete(filesystem);
  					filesystem = new_filesystem;
  					new_filesystem = NULL;
  					Thread::wait_to_finish(thread);
  					memdelete(thread);
  					thread = NULL;
  					_update_scan_actions();
  					emit_signal("filesystem_changed");
  					emit_signal("sources_changed", sources_changed.size() > 0);
  					_queue_update_script_classes();
  					first_scan = false;
  				}
  			}
  		} break;
  	}
  }
  
  bool EditorFileSystem::is_scanning() const {
  
  	return scanning || scanning_changes;
  }
  float EditorFileSystem::get_scanning_progress() const {
  
  	return scan_total;
  }
  
  EditorFileSystemDirectory *EditorFileSystem::get_filesystem() {
  
  	return filesystem;
  }
  
  void EditorFileSystem::_save_filesystem_cache(EditorFileSystemDirectory *p_dir, FileAccess *p_file) {
  
  	if (!p_dir)
  		return; //none
  	p_file->store_line("::" + p_dir->get_path() + "::" + String::num(p_dir->modified_time));
  
  	for (int i = 0; i < p_dir->files.size(); i++) {
  
  		if (p_dir->files[i]->import_group_file != String()) {
  			group_file_cache.insert(p_dir->files[i]->import_group_file);
  		}
  		String s = p_dir->files[i]->file + "::" + p_dir->files[i]->type + "::" + itos(p_dir->files[i]->modified_time) + "::" + itos(p_dir->files[i]->import_modified_time) + "::" + itos(p_dir->files[i]->import_valid) + "::" + p_dir->files[i]->import_group_file + "::" + p_dir->files[i]->script_class_name + "<>" + p_dir->files[i]->script_class_extends + "<>" + p_dir->files[i]->script_class_icon_path;
  		s += "::";
  		for (int j = 0; j < p_dir->files[i]->deps.size(); j++) {
  
  			if (j > 0)
  				s += "<>";
  			s += p_dir->files[i]->deps[j];
  		}
  
  		p_file->store_line(s);
  	}
  
  	for (int i = 0; i < p_dir->subdirs.size(); i++) {
  
  		_save_filesystem_cache(p_dir->subdirs[i], p_file);
  	}
  }
  
  bool EditorFileSystem::_find_file(const String &p_file, EditorFileSystemDirectory **r_d, int &r_file_pos) const {
  	//todo make faster
  
  	if (!filesystem || scanning)
  		return false;
  
  	String f = ProjectSettings::get_singleton()->localize_path(p_file);
  
  	if (!f.begins_with("res://"))
  		return false;
  	f = f.substr(6, f.length());
  	f = f.replace("\\", "/");
  
  	Vector<String> path = f.split("/");
  
  	if (path.size() == 0)
  		return false;
  	String file = path[path.size() - 1];
  	path.resize(path.size() - 1);
  
  	EditorFileSystemDirectory *fs = filesystem;
  
  	for (int i = 0; i < path.size(); i++) {
  
  		if (path[i].begins_with("."))
  			return false;
  
  		int idx = -1;
  		for (int j = 0; j < fs->get_subdir_count(); j++) {
  
  			if (fs->get_subdir(j)->get_name() == path[i]) {
  				idx = j;
  				break;
  			}
  		}
  
  		if (idx == -1) {
  			//does not exist, create i guess?
  			EditorFileSystemDirectory *efsd = memnew(EditorFileSystemDirectory);
  
  			efsd->name = path[i];
  			efsd->parent = fs;
  
  			int idx2 = 0;
  			for (int j = 0; j < fs->get_subdir_count(); j++) {
  
  				if (efsd->name < fs->get_subdir(j)->get_name())
  					break;
  				idx2++;
  			}
  
  			if (idx2 == fs->get_subdir_count())
  				fs->subdirs.push_back(efsd);
  			else
  				fs->subdirs.insert(idx2, efsd);
  			fs = efsd;
  		} else {
  
  			fs = fs->get_subdir(idx);
  		}
  	}
  
  	int cpos = -1;
  	for (int i = 0; i < fs->files.size(); i++) {
  
  		if (fs->files[i]->file == file) {
  			cpos = i;
  			break;
  		}
  	}
  
  	r_file_pos = cpos;
  	*r_d = fs;
  
  	return cpos != -1;
  }
  
  String EditorFileSystem::get_file_type(const String &p_file) const {
  
  	EditorFileSystemDirectory *fs = NULL;
  	int cpos = -1;
  
  	if (!_find_file(p_file, &fs, cpos)) {
  
  		return "";
  	}
  
  	return fs->files[cpos]->type;
  }
  
  EditorFileSystemDirectory *EditorFileSystem::find_file(const String &p_file, int *r_index) const {
  
  	if (!filesystem || scanning)
  		return NULL;
  
  	EditorFileSystemDirectory *fs = NULL;
  	int cpos = -1;
  	if (!_find_file(p_file, &fs, cpos)) {
  
  		return NULL;
  	}
  
  	if (r_index)
  		*r_index = cpos;
  
  	return fs;
  }
  
  EditorFileSystemDirectory *EditorFileSystem::get_filesystem_path(const String &p_path) {
  
  	if (!filesystem || scanning)
  		return NULL;
  
  	String f = ProjectSettings::get_singleton()->localize_path(p_path);
  
  	if (!f.begins_with("res://"))
  		return NULL;
  
  	f = f.substr(6, f.length());
  	f = f.replace("\\", "/");
  	if (f == String())
  		return filesystem;
  
  	if (f.ends_with("/"))
  		f = f.substr(0, f.length() - 1);
  
  	Vector<String> path = f.split("/");
  
  	if (path.size() == 0)
  		return NULL;
  
  	EditorFileSystemDirectory *fs = filesystem;
  
  	for (int i = 0; i < path.size(); i++) {
  
  		int idx = -1;
  		for (int j = 0; j < fs->get_subdir_count(); j++) {
  
  			if (fs->get_subdir(j)->get_name() == path[i]) {
  				idx = j;
  				break;
  			}
  		}
  
  		if (idx == -1) {
  			return NULL;
  		} else {
  
  			fs = fs->get_subdir(idx);
  		}
  	}
  
  	return fs;
  }
  
  void EditorFileSystem::_save_late_updated_files() {
  	//files that already existed, and were modified, need re-scanning for dependencies upon project restart. This is done via saving this special file
  	String fscache = EditorSettings::get_singleton()->get_project_settings_dir().plus_file("filesystem_update4");
  	FileAccessRef f = FileAccess::open(fscache, FileAccess::WRITE);
  	for (Set<String>::Element *E = late_update_files.front(); E; E = E->next()) {
  		f->store_line(E->get());
  	}
  }
  
  Vector<String> EditorFileSystem::_get_dependencies(const String &p_path) {
  
  	List<String> deps;
  	ResourceLoader::get_dependencies(p_path, &deps);
  
  	Vector<String> ret;
  	for (List<String>::Element *E = deps.front(); E; E = E->next()) {
  		ret.push_back(E->get());
  	}
  
  	return ret;
  }
  
  String EditorFileSystem::_get_global_script_class(const String &p_type, const String &p_path, String *r_extends, String *r_icon_path) const {
  
  	for (int i = 0; i < ScriptServer::get_language_count(); i++) {
  		if (ScriptServer::get_language(i)->handles_global_class_type(p_type)) {
  			String global_name;
  			String extends;
  			String icon_path;
  
  			global_name = ScriptServer::get_language(i)->get_global_class_name(p_path, &extends, &icon_path);
  			*r_extends = extends;
  			*r_icon_path = icon_path;
  			return global_name;
  		}
  	}
  	*r_extends = String();
  	*r_icon_path = String();
  	return String();
  }
  
  void EditorFileSystem::_scan_script_classes(EditorFileSystemDirectory *p_dir) {
  	int filecount = p_dir->files.size();
  	const EditorFileSystemDirectory::FileInfo *const *files = p_dir->files.ptr();
  	for (int i = 0; i < filecount; i++) {
  		if (files[i]->script_class_name == String()) {
  			continue;
  		}
  
  		String lang;
  		for (int j = 0; j < ScriptServer::get_language_count(); j++) {
  			if (ScriptServer::get_language(j)->handles_global_class_type(files[i]->type)) {
  				lang = ScriptServer::get_language(j)->get_name();
  			}
  		}
  		ScriptServer::add_global_class(files[i]->script_class_name, files[i]->script_class_extends, lang, p_dir->get_file_path(i));
  		EditorNode::get_editor_data().script_class_set_icon_path(files[i]->script_class_name, files[i]->script_class_icon_path);
  		EditorNode::get_editor_data().script_class_set_name(files[i]->file, files[i]->script_class_name);
  	}
  	for (int i = 0; i < p_dir->get_subdir_count(); i++) {
  		_scan_script_classes(p_dir->get_subdir(i));
  	}
  }
  
  void EditorFileSystem::update_script_classes() {
  
  	if (!update_script_classes_queued)
  		return;
  
  	update_script_classes_queued = false;
  	ScriptServer::global_classes_clear();
  	if (get_filesystem()) {
  		_scan_script_classes(get_filesystem());
  	}
  
  	ScriptServer::save_global_classes();
  	EditorNode::get_editor_data().script_class_save_icon_paths();
  
  	// Rescan custom loaders and savers.
  	// Doing the following here because the `filesystem_changed` signal fires multiple times and isn't always followed by script classes update.
  	// So I thought it's better to do this when script classes really get updated
  	ResourceLoader::remove_custom_loaders();
  	ResourceLoader::add_custom_loaders();
  	ResourceSaver::remove_custom_savers();
  	ResourceSaver::add_custom_savers();
  }
  
  void EditorFileSystem::_queue_update_script_classes() {
  	if (update_script_classes_queued) {
  		return;
  	}
  
  	update_script_classes_queued = true;
  	call_deferred("update_script_classes");
  }
  
  void EditorFileSystem::update_file(const String &p_file) {
  
  	EditorFileSystemDirectory *fs = NULL;
  	int cpos = -1;
  
  	if (!_find_file(p_file, &fs, cpos)) {
  
  		if (!fs)
  			return;
  	}
  
  	if (!FileAccess::exists(p_file)) {
  		//was removed
  		_delete_internal_files(p_file);
  		if (cpos != -1) { // Might've never been part of the editor file system (*.* files deleted in Open dialog).
  			memdelete(fs->files[cpos]);
  			fs->files.remove(cpos);
  		}
  
  		call_deferred("emit_signal", "filesystem_changed"); //update later
  		_queue_update_script_classes();
  		return;
  	}
  
  	String type = ResourceLoader::get_resource_type(p_file);
  
  	if (cpos == -1) {
  
  		//the file did not exist, it was added
  
  		late_added_files.insert(p_file); //remember that it was added. This mean it will be scanned and imported on editor restart
  		int idx = 0;
  
  		for (int i = 0; i < fs->files.size(); i++) {
  			if (p_file < fs->files[i]->file)
  				break;
  			idx++;
  		}
  
  		EditorFileSystemDirectory::FileInfo *fi = memnew(EditorFileSystemDirectory::FileInfo);
  		fi->file = p_file.get_file();
  		fi->import_modified_time = 0;
  		fi->import_valid = ResourceLoader::is_import_valid(p_file);
  
  		if (idx == fs->files.size()) {
  			fs->files.push_back(fi);
  		} else {
  
  			fs->files.insert(idx, fi);
  		}
  		cpos = idx;
  	} else {
  
  		//the file exists and it was updated, and was not added in this step.
  		//this means we must force upon next restart to scan it again, to get proper type and dependencies
  		late_update_files.insert(p_file);
  		_save_late_updated_files(); //files need to be updated in the re-scan
  	}
  
  	fs->files[cpos]->type = type;
  	fs->files[cpos]->script_class_name = _get_global_script_class(type, p_file, &fs->files[cpos]->script_class_extends, &fs->files[cpos]->script_class_icon_path);
  	fs->files[cpos]->import_group_file = ResourceLoader::get_import_group_file(p_file);
  	fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
  	fs->files[cpos]->deps = _get_dependencies(p_file);
  	fs->files[cpos]->import_valid = ResourceLoader::is_import_valid(p_file);
  
  	// Update preview
  	EditorResourcePreview::get_singleton()->check_for_invalidation(p_file);
  
  	call_deferred("emit_signal", "filesystem_changed"); //update later
  	_queue_update_script_classes();
  }
  
  Error EditorFileSystem::_reimport_group(const String &p_group_file, const Vector<String> &p_files) {
  
  	String importer_name;
  
  	Map<String, Map<StringName, Variant> > source_file_options;
  	Map<String, String> base_paths;
  	for (int i = 0; i < p_files.size(); i++) {
  
  		Ref<ConfigFile> config;
  		config.instance();
  		Error err = config->load(p_files[i] + ".import");
  		ERR_CONTINUE(err != OK);
  		ERR_CONTINUE(!config->has_section_key("remap", "importer"));
  		String file_importer_name = config->get_value("remap", "importer");
  		ERR_CONTINUE(file_importer_name == String());
  
  		if (importer_name != String() && importer_name != file_importer_name) {
  			print_line("one importer: " + importer_name + " the other: " + file_importer_name);
  			EditorNode::get_singleton()->show_warning(vformat(TTR("There are multiple importers for different types pointing to file %s, import aborted"), p_group_file));
  			ERR_FAIL_V(ERR_FILE_CORRUPT);
  		}
  
  		source_file_options[p_files[i]] = Map<StringName, Variant>();
  		importer_name = file_importer_name;
  
  		Ref<ResourceImporter> importer = ResourceFormatImporter::get_singleton()->get_importer_by_name(importer_name);
  		ERR_FAIL_COND_V(!importer.is_valid(), ERR_FILE_CORRUPT);
  		List<ResourceImporter::ImportOption> options;
  		importer->get_import_options(&options);
  		//set default values
  		for (List<ResourceImporter::ImportOption>::Element *E = options.front(); E; E = E->next()) {
  
  			source_file_options[p_files[i]][E->get().option.name] = E->get().default_value;
  		}
  
  		if (config->has_section("params")) {
  			List<String> sk;
  			config->get_section_keys("params", &sk);
  			for (List<String>::Element *E = sk.front(); E; E = E->next()) {
  				String param = E->get();
  				Variant value = config->get_value("params", param);
  				//override with whathever is in file
  				source_file_options[p_files[i]][param] = value;
  			}
  		}
  
  		base_paths[p_files[i]] = ResourceFormatImporter::get_singleton()->get_import_base_path(p_files[i]);
  	}
  
  	ERR_FAIL_COND_V(importer_name == String(), ERR_UNCONFIGURED);
  
  	Ref<ResourceImporter> importer = ResourceFormatImporter::get_singleton()->get_importer_by_name(importer_name);
  
  	Error err = importer->import_group_file(p_group_file, source_file_options, base_paths);
  
  	//all went well, overwrite config files with proper remaps and md5s
  	for (Map<String, Map<StringName, Variant> >::Element *E = source_file_options.front(); E; E = E->next()) {
  
  		const String &file = E->key();
  		String base_path = ResourceFormatImporter::get_singleton()->get_import_base_path(file);
  		FileAccessRef f = FileAccess::open(file + ".import", FileAccess::WRITE);
  		ERR_FAIL_COND_V(!f, ERR_FILE_CANT_OPEN);
  
  		//write manually, as order matters ([remap] has to go first for performance).
  		f->store_line("[remap]");
  		f->store_line("");
  		f->store_line("importer=\"" + importer->get_importer_name() + "\"");
  		if (importer->get_resource_type() != "") {
  			f->store_line("type=\"" + importer->get_resource_type() + "\"");
  		}
  
  		Vector<String> dest_paths;
  
  		if (err == OK) {
  			String path = base_path + "." + importer->get_save_extension();
  			f->store_line("path=\"" + path + "\"");
  			dest_paths.push_back(path);
  		}
  
  		f->store_line("group_file=" + Variant(p_group_file).get_construct_string());
  
  		if (err == OK) {
  			f->store_line("valid=true");
  		} else {
  			f->store_line("valid=false");
  		}
  		f->store_line("[deps]\n");
  
  		f->store_line("");
  
  		f->store_line("source_file=" + Variant(file).get_construct_string());
  		if (dest_paths.size()) {
  			Array dp;
  			for (int i = 0; i < dest_paths.size(); i++) {
  				dp.push_back(dest_paths[i]);
  			}
  			f->store_line("dest_files=" + Variant(dp).get_construct_string() + "\n");
  		}
  		f->store_line("[params]");
  		f->store_line("");
  
  		//store options in provided order, to avoid file changing. Order is also important because first match is accepted first.
  
  		List<ResourceImporter::ImportOption> options;
  		importer->get_import_options(&options);
  		//set default values
  		for (List<ResourceImporter::ImportOption>::Element *F = options.front(); F; F = F->next()) {
  
  			String base = F->get().option.name;
  			Variant v = F->get().default_value;
  			if (source_file_options[file].has(base)) {
  				v = source_file_options[file][base];
  			}
  			String value;
  			VariantWriter::write_to_string(v, value);
  			f->store_line(base + "=" + value);
  		}
  
  		f->close();
  
  		// Store the md5's of the various files. These are stored separately so that the .import files can be version controlled.
  		FileAccessRef md5s = FileAccess::open(base_path + ".md5", FileAccess::WRITE);
  		ERR_FAIL_COND_V(!md5s, ERR_FILE_CANT_OPEN);
  
  		md5s->store_line("source_md5=\"" + FileAccess::get_md5(file) + "\"");
  		if (dest_paths.size()) {
  			md5s->store_line("dest_md5=\"" + FileAccess::get_multiple_md5(dest_paths) + "\"\n");
  		}
  		md5s->close();
  
  		EditorFileSystemDirectory *fs = NULL;
  		int cpos = -1;
  		bool found = _find_file(file, &fs, cpos);
  		ERR_FAIL_COND_V(!found, ERR_UNCONFIGURED);
  
  		//update modified times, to avoid reimport
  		fs->files[cpos]->modified_time = FileAccess::get_modified_time(file);
  		fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(file + ".import");
  		fs->files[cpos]->deps = _get_dependencies(file);
  		fs->files[cpos]->type = importer->get_resource_type();
  		fs->files[cpos]->import_valid = err == OK;
  
  		//if file is currently up, maybe the source it was loaded from changed, so import math must be updated for it
  		//to reload properly
  		if (ResourceCache::has(file)) {
  
  			Resource *r = ResourceCache::get(file);
  
  			if (r->get_import_path() != String()) {
  
  				String dst_path = ResourceFormatImporter::get_singleton()->get_internal_resource_path(file);
  				r->set_import_path(dst_path);
  				r->set_import_last_modified_time(0);
  			}
  		}
  
  		EditorResourcePreview::get_singleton()->check_for_invalidation(file);
  	}
  
  	return err;
  }
  
  void EditorFileSystem::_reimport_file(const String &p_file) {
  
  	EditorFileSystemDirectory *fs = NULL;
  	int cpos = -1;
  	bool found = _find_file(p_file, &fs, cpos);
  	ERR_FAIL_COND(!found);
  
  	//try to obtain existing params
  
  	Map<StringName, Variant> params;
  	String importer_name;
  
  	if (FileAccess::exists(p_file + ".import")) {
  		//use existing
  		Ref<ConfigFile> cf;
  		cf.instance();
  		Error err = cf->load(p_file + ".import");
  		if (err == OK) {
  			if (cf->has_section("params")) {
  				List<String> sk;
  				cf->get_section_keys("params", &sk);
  				for (List<String>::Element *E = sk.front(); E; E = E->next()) {
  					params[E->get()] = cf->get_value("params", E->get());
  				}
  			}
  			if (cf->has_section("remap")) {
  				importer_name = cf->get_value("remap", "importer");
  			}
  		}
  
  	} else {
  		late_added_files.insert(p_file); //imported files do not call update_file(), but just in case..
  	}
  
  	Ref<ResourceImporter> importer;
  	bool load_default = false;
  	//find the importer
  	if (importer_name != "") {
  		importer = ResourceFormatImporter::get_singleton()->get_importer_by_name(importer_name);
  	}
  
  	if (importer.is_null()) {
  		//not found by name, find by extension
  		importer = ResourceFormatImporter::get_singleton()->get_importer_by_extension(p_file.get_extension());
  		load_default = true;
  		if (importer.is_null()) {
  			ERR_PRINT("BUG: File queued for import, but can't be imported!");
  			ERR_FAIL();
  		}
  	}
  
  	//mix with default params, in case a parameter is missing
  
  	List<ResourceImporter::ImportOption> opts;
  	importer->get_import_options(&opts);
  	for (List<ResourceImporter::ImportOption>::Element *E = opts.front(); E; E = E->next()) {
  		if (!params.has(E->get().option.name)) { //this one is not present
  			params[E->get().option.name] = E->get().default_value;
  		}
  	}
  
  	if (load_default && ProjectSettings::get_singleton()->has_setting("importer_defaults/" + importer->get_importer_name())) {
  		//use defaults if exist
  		Dictionary d = ProjectSettings::get_singleton()->get("importer_defaults/" + importer->get_importer_name());
  		List<Variant> v;
  		d.get_key_list(&v);
  
  		for (List<Variant>::Element *E = v.front(); E; E = E->next()) {
  			params[E->get()] = d[E->get()];
  		}
  	}
  
  	//finally, perform import!!
  	String base_path = ResourceFormatImporter::get_singleton()->get_import_base_path(p_file);
  
  	List<String> import_variants;
  	List<String> gen_files;
  	Variant metadata;
  	Error err = importer->import(p_file, base_path, params, &import_variants, &gen_files, &metadata);
  
  	if (err != OK) {
  		ERR_PRINTS("Error importing: " + p_file);
  	}
  
  	//as import is complete, save the .import file
  
  	FileAccess *f = FileAccess::open(p_file + ".import", FileAccess::WRITE);
  	ERR_FAIL_COND(!f);
  
  	//write manually, as order matters ([remap] has to go first for performance).
  	f->store_line("[remap]");
  	f->store_line("");
  	f->store_line("importer=\"" + importer->get_importer_name() + "\"");
  	if (importer->get_resource_type() != "") {
  		f->store_line("type=\"" + importer->get_resource_type() + "\"");
  	}
  
  	Vector<String> dest_paths;
  
  	if (err == OK) {
  
  		if (importer->get_save_extension() == "") {
  			//no path
  		} else if (import_variants.size()) {
  			//import with variants
  			for (List<String>::Element *E = import_variants.front(); E; E = E->next()) {
  
  				String path = base_path.c_escape() + "." + E->get() + "." + importer->get_save_extension();
  
  				f->store_line("path." + E->get() + "=\"" + path + "\"");
  				dest_paths.push_back(path);
  			}
  		} else {
  			String path = base_path + "." + importer->get_save_extension();
  			f->store_line("path=\"" + path + "\"");
  			dest_paths.push_back(path);
  		}
  
  	} else {
  
  		f->store_line("valid=false");
  	}
  
  	if (metadata != Variant()) {
  		f->store_line("metadata=" + metadata.get_construct_string());
  	}
  
  	f->store_line("");
  
  	f->store_line("[deps]\n");
  
  	if (gen_files.size()) {
  		Array genf;
  		for (List<String>::Element *E = gen_files.front(); E; E = E->next()) {
  			genf.push_back(E->get());
  			dest_paths.push_back(E->get());
  		}
  
  		String value;
  		VariantWriter::write_to_string(genf, value);
  		f->store_line("files=" + value);
  		f->store_line("");
  	}
  
  	f->store_line("source_file=" + Variant(p_file).get_construct_string());
  
  	if (dest_paths.size()) {
  		Array dp;
  		for (int i = 0; i < dest_paths.size(); i++) {
  			dp.push_back(dest_paths[i]);
  		}
  		f->store_line("dest_files=" + Variant(dp).get_construct_string() + "\n");
  	}
  
  	f->store_line("[params]");
  	f->store_line("");
  
  	//store options in provided order, to avoid file changing. Order is also important because first match is accepted first.
  
  	for (List<ResourceImporter::ImportOption>::Element *E = opts.front(); E; E = E->next()) {
  
  		String base = E->get().option.name;
  		String value;
  		VariantWriter::write_to_string(params[base], value);
  		f->store_line(base + "=" + value);
  	}
  
  	f->close();
  	memdelete(f);
  
  	// Store the md5's of the various files. These are stored separately so that the .import files can be version controlled.
  	FileAccess *md5s = FileAccess::open(base_path + ".md5", FileAccess::WRITE);
  	ERR_FAIL_COND(!md5s);
  	md5s->store_line("source_md5=\"" + FileAccess::get_md5(p_file) + "\"");
  	if (dest_paths.size()) {
  		md5s->store_line("dest_md5=\"" + FileAccess::get_multiple_md5(dest_paths) + "\"\n");
  	}
  	md5s->close();
  	memdelete(md5s);
  
  	//update modified times, to avoid reimport
  	fs->files[cpos]->modified_time = FileAccess::get_modified_time(p_file);
  	fs->files[cpos]->import_modified_time = FileAccess::get_modified_time(p_file + ".import");
  	fs->files[cpos]->deps = _get_dependencies(p_file);
  	fs->files[cpos]->type = importer->get_resource_type();
  	fs->files[cpos]->import_valid = ResourceLoader::is_import_valid(p_file);
  
  	//if file is currently up, maybe the source it was loaded from changed, so import math must be updated for it
  	//to reload properly
  	if (ResourceCache::has(p_file)) {
  
  		Resource *r = ResourceCache::get(p_file);
  
  		if (r->get_import_path() != String()) {
  
  			String dst_path = ResourceFormatImporter::get_singleton()->get_internal_resource_path(p_file);
  			r->set_import_path(dst_path);
  			r->set_import_last_modified_time(0);
  		}
  	}
  
  	EditorResourcePreview::get_singleton()->check_for_invalidation(p_file);
  }
  
  void EditorFileSystem::_find_group_files(EditorFileSystemDirectory *efd, Map<String, Vector<String> > &group_files, Set<String> &groups_to_reimport) {
  
  	int fc = efd->files.size();
  	const EditorFileSystemDirectory::FileInfo *const *files = efd->files.ptr();
  	for (int i = 0; i < fc; i++) {
  		if (groups_to_reimport.has(files[i]->import_group_file)) {
  			if (!group_files.has(files[i]->import_group_file)) {
  				group_files[files[i]->import_group_file] = Vector<String>();
  			}
  			group_files[files[i]->import_group_file].push_back(efd->get_file_path(i));
  		}
  	}
  
  	for (int i = 0; i < efd->get_subdir_count(); i++) {
  		_find_group_files(efd->get_subdir(i), group_files, groups_to_reimport);
  	}
  }
  
  void EditorFileSystem::reimport_files(const Vector<String> &p_files) {
  
  	{ //check that .import folder exists
  		DirAccess *da = DirAccess::open("res://");
  		if (da->change_dir(".import") != OK) {
  			Error err = da->make_dir(".import");
  			if (err) {
  				memdelete(da);
  				ERR_EXPLAIN("Failed to create 'res://.import' folder.");
  				ERR_FAIL();
  			}
  		}
  		memdelete(da);
  	}
  
  	importing = true;
  	EditorProgress pr("reimport", TTR("(Re)Importing Assets"), p_files.size());
  
  	Vector<ImportFile> files;
  	Set<String> groups_to_reimport;
  
  	for (int i = 0; i < p_files.size(); i++) {
  
  		String group_file = ResourceFormatImporter::get_singleton()->get_import_group_file(p_files[i]);
  
  		if (group_file_cache.has(p_files[i])) {
  			//maybe the file itself is a group!
  			groups_to_reimport.insert(p_files[i]);
  			//groups do not belong to grups
  			group_file = String();
  		} else if (group_file != String()) {
  			//it's a group file, add group to import and skip this file
  			groups_to_reimport.insert(group_file);
  		} else {
  			//it's a regular file
  			ImportFile ifile;
  			ifile.path = p_files[i];
  			ifile.order = ResourceFormatImporter::get_singleton()->get_import_order(p_files[i]);
  			files.push_back(ifile);
  		}
  
  		//group may have changed, so also update group reference
  		EditorFileSystemDirectory *fs = NULL;
  		int cpos = -1;
  		if (_find_file(p_files[i], &fs, cpos)) {
  
  			fs->files.write[cpos]->import_group_file = group_file;
  		}
  	}
  
  	files.sort();
  
  	for (int i = 0; i < files.size(); i++) {
  		pr.step(files[i].path.get_file(), i);
  		_reimport_file(files[i].path);
  	}
  
  	//reimport groups
  
  	if (groups_to_reimport.size()) {
  		Map<String, Vector<String> > group_files;
  		_find_group_files(filesystem, group_files, groups_to_reimport);
  		for (Map<String, Vector<String> >::Element *E = group_files.front(); E; E = E->next()) {
  
  			Error err = _reimport_group(E->key(), E->get());
  			if (err == OK) {
  				_reimport_file(E->key());
  			}
  		}
  	}
  
  	_save_filesystem_cache();
  	importing = false;
  	if (!is_scanning()) {
  		emit_signal("filesystem_changed");
  	}
  
  	emit_signal("resources_reimported", p_files);
  }
  
  Error EditorFileSystem::_resource_import(const String &p_path) {
  
  	Vector<String> files;
  	files.push_back(p_path);
  
  	singleton->update_file(p_path);
  	singleton->reimport_files(files);
  
  	return OK;
  }
  
  bool EditorFileSystem::is_group_file(const String &p_path) const {
  	return group_file_cache.has(p_path);
  }
  
  void EditorFileSystem::_move_group_files(EditorFileSystemDirectory *efd, const String &p_group_file, const String &p_new_location) {
  
  	int fc = efd->files.size();
  	EditorFileSystemDirectory::FileInfo *const *files = efd->files.ptrw();
  	for (int i = 0; i < fc; i++) {
  
  		if (files[i]->import_group_file == p_group_file) {
  
  			files[i]->import_group_file = p_new_location;
  
  			Ref<ConfigFile> config;
  			config.instance();
  			String path = efd->get_file_path(i) + ".import";
  			Error err = config->load(path);
  			if (err != OK) {
  				continue;
  			}
  			if (config->has_section_key("remap", "group_file")) {
  
  				config->set_value("remap", "group_file", p_new_location);
  			}
  
  			List<String> sk;
  			config->get_section_keys("params", &sk);
  			for (List<String>::Element *E = sk.front(); E; E = E->next()) {
  				//not very clean, but should work
  				String param = E->get();
  				String value = config->get_value("params", param);
  				if (value == p_group_file) {
  					config->set_value("params", param, p_new_location);
  				}
  			}
  
  			config->save(path);
  		}
  	}
  
  	for (int i = 0; i < efd->get_subdir_count(); i++) {
  		_move_group_files(efd->get_subdir(i), p_group_file, p_new_location);
  	}
  }
  
  void EditorFileSystem::move_group_file(const String &p_path, const String &p_new_path) {
  
  	if (get_filesystem()) {
  		_move_group_files(get_filesystem(), p_path, p_new_path);
  		if (group_file_cache.has(p_path)) {
  			group_file_cache.erase(p_path);
  			group_file_cache.insert(p_new_path);
  		}
  	}
  }
  
  void EditorFileSystem::_bind_methods() {
  
  	ClassDB::bind_method(D_METHOD("get_filesystem"), &EditorFileSystem::get_filesystem);
  	ClassDB::bind_method(D_METHOD("is_scanning"), &EditorFileSystem::is_scanning);
  	ClassDB::bind_method(D_METHOD("get_scanning_progress"), &EditorFileSystem::get_scanning_progress);
  	ClassDB::bind_method(D_METHOD("scan"), &EditorFileSystem::scan);
  	ClassDB::bind_method(D_METHOD("scan_sources"), &EditorFileSystem::scan_changes);
  	ClassDB::bind_method(D_METHOD("update_file", "path"), &EditorFileSystem::update_file);
  	ClassDB::bind_method(D_METHOD("get_filesystem_path", "path"), &EditorFileSystem::get_filesystem_path);
  	ClassDB::bind_method(D_METHOD("get_file_type", "path"), &EditorFileSystem::get_file_type);
  	ClassDB::bind_method(D_METHOD("update_script_classes"), &EditorFileSystem::update_script_classes);
  
  	ADD_SIGNAL(MethodInfo("filesystem_changed"));
  	ADD_SIGNAL(MethodInfo("sources_changed", PropertyInfo(Variant::BOOL, "exist")));
  	ADD_SIGNAL(MethodInfo("resources_reimported", PropertyInfo(Variant::POOL_STRING_ARRAY, "resources")));
  	ADD_SIGNAL(MethodInfo("resources_reload", PropertyInfo(Variant::POOL_STRING_ARRAY, "resources")));
  }
  
  void EditorFileSystem::_update_extensions() {
  
  	valid_extensions.clear();
  	import_extensions.clear();
  
  	List<String> extensionsl;
  	ResourceLoader::get_recognized_extensions_for_type("", &extensionsl);
  	for (List<String>::Element *E = extensionsl.front(); E; E = E->next()) {
  
  		valid_extensions.insert(E->get());
  	}
  
  	extensionsl.clear();
  	ResourceFormatImporter::get_singleton()->get_recognized_extensions(&extensionsl);
  	for (List<String>::Element *E = extensionsl.front(); E; E = E->next()) {
  
  		import_extensions.insert(E->get());
  	}
  }
  
  EditorFileSystem::EditorFileSystem() {
  
  	ResourceLoader::import = _resource_import;
  	reimport_on_missing_imported_files = GLOBAL_DEF("editor/reimport_missing_imported_files", true);
  
  	singleton = this;
  	filesystem = memnew(EditorFileSystemDirectory); //like, empty
  	filesystem->parent = NULL;
  
  	thread = NULL;
  	scanning = false;
  	importing = false;
  	use_threads = true;
  	thread_sources = NULL;
  	new_filesystem = NULL;
  
  	abort_scan = false;
  	scanning_changes = false;
  	scanning_changes_done = false;
  
  	DirAccess *da = DirAccess::create(DirAccess::ACCESS_RESOURCES);
  	if (da->change_dir("res://.import") != OK) {
  		da->make_dir("res://.import");
  	}
  	// This should probably also work on Unix and use the string it returns for FAT32 or exFAT
  	using_fat32_or_exfat = (da->get_filesystem_type() == "FAT32" || da->get_filesystem_type() == "exFAT");
  	memdelete(da);
  
  	scan_total = 0;
  	update_script_classes_queued = false;
  	first_scan = true;
  	revalidate_import_files = false;
  }
  
  EditorFileSystem::~EditorFileSystem() {
  }
  